Vet Parasitol. 2009 Aug 15. [Epub ahead of print]
Toxoplasma gondii: Prototype immunization of lambs against formation of muscle and brain cysts
Falcón J, Freyre A.
Laboratory for Toxoplasmosis, Dept. Parasitology, College of Veterinary Sciences, Montevideo, Uruguay.
Nine lambs were immunized with 10(6) oocysts of the relatively avirulent ME-49 strain of Toxoplasma gondii, and were challenged 45 days later with 4x10(6) oocysts of the M3 strain of this parasite. Less than 5 tissue cysts of the M3 strain formed per 8g of muscle - if any - judging from a bioassay in mice in which all mice survived. In contrast, mortality occurred in mice fed muscle specimens from 4 lambs that had not been immunized with ME-49 prior to challenge with the M3 strain. This finding suggests the possibility of creating a vaccine for lambs that could diminish or abolish lamb and mutton as sources of human infection with T. gondii, and which could also prevent toxoplasmosis abortion in sheep.
PMID: 19729248 [PubMed - as supplied by publisher]